Compilation strategy

[Paulo Pinto]

On Monday, 17 December 2012 at 09:58:28 UTC, Walter Bright wrote:
> On 12/17/2012 1:35 AM, Paulo Pinto wrote:
>> It suffices to get the general algorithm behind the code, and 
>> that is impossible
>> to hide, unless the developer resorts to cryptography.
>
> I'll say again, with enough effort, an expert *can* decompile 
> object files by hand. You can't make a tool to do that for you, 
> though.
>
> It can also be pretty damned challenging to figure out the 
> algorithm used in a bit of non-trivial assembler after it's 
> gone through a modern compiler optimizer.
>
> I know nobody here wants to believe me, but it is trivial to 
> automatically turn Java bytecode back into source code.
>
> Google "convert .class file to .java":
>
>     http://java.decompiler.free.fr/
>
> Now try:
>
> Google "convert object file to C"
>
> If you don't believe me, a guy who's been working on C 
> compilers for 30 years, and who also wrote a Java compiler, 
> that should be a helpful data point.

Of course I believe you and respect your experience.

The point I was trying to make is that if someone really wants 
your code, they will get it, even if that means reading assembly 
instructions manually.

In one company I used to work, we rewrote the TCL parser to read 
encrypted files to avoid delivering text to the customer, hoping 
that it would be enough to detain most people.

--
Paulo